Thermoelectric space heaters

ABSTRACT

Disclosed are various thermoelectric heaters. A thermal transfer component has a first plate attached to a second plate. A heating channel is formed by at least one of the first plate or the second plate of the thermal transfer component. The heating channel is between the first plate and the second plate of the thermal transfer component. A heating element is within the heating channel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to CN Application No. 201610527750.3, filed on Jul. 1, 2016, which is incorporated by reference herein in its entirety.

BACKGROUND

The temperature in an area or room can be raised to a more desirable level using an electrical heater. Thermal transfer can be grouped into three broad categories: conduction, convection, and radiation. Thermal conduction generally refers to transfer of thermal energy through physical contact. Thermal convection generally refers to transfer of thermal energy through heating a fluid, such as liquid or gas (e.g. air). As the air in a room is heated, the warmer air rises, displacing cooler fluid and causing the air to circulate. Thermal radiation generally refers to transfer of thermal energy using electromagnetic waves. Raising the temperature of an object can cause it to radiate infrared waves, which can come into contact with another object causing a heating effect.

Some heaters, such as oil filled radiators, can cause a combination of convection heating and radiant heating to heat a room. However, using oil can cause problems in manufacture and end use. If seals fail, the oil can leak out, causing problems for the end user. Oil seals can require costly manufacturing requirements, which can be burdensome for manufacturers to implement.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a drawing of an example of a thermoelectric space heater.

FIG. 2 is a drawing of an example of a thermal transfer component of the thermoelectric space heater.

FIG. 3. is a drawing of an example of an exploded view of the thermal transfer component of the thermoelectric space heater.

FIG. 4 is a drawing of an example of a sectional view of the thermal transfer component of the thermoelectric space heater.

FIG. 5 is a drawing of a heating element of the thermoelectric space heater.

FIG. 6 is a drawing of another example of a thermal transfer component of the thermoelectric space heater.

DETAILED DESCRIPTION

The present disclosure relates to thermoelectric space heaters. The heaters described herein can provide fast heating by distributing the heating element throughout the thermal transfer fin or component. This can overcome the long heating times of existing oil-filled heaters that have a heating element only across a bottom of the heater, requiring oil convection within the heater to distribute heating. The thermoelectric space heaters described can heat at nominal power for long durations, without causing the outer edges to go over safe operating temperatures (e.g., 85° C.). The design of the heating element and its arrangement in a channel of the thermoelectric space heater can allay the danger of causing scorching or burning. Also, a tip-over switch may not be needed, for example, by using lower resistance per unit length for the heating element in a lower temperature region and a higher resistance per unit length heating element for a higher temperature region in a heating channel. The structure of the thermoelectric space heaters described in the present disclosure is robust, has few parts, assembles conveniently, and has low production cost.

Referring now to the figures, FIG. 1 shows an example of a thermoelectric space heater 100. The thermoelectric space heater 100 has a number of thermal fins or thermal transfer components 106A-106G (individually, “thermal transfer component 106,” collectively, “thermal transfer components 106”). The thermal transfer components 106 can be connected to each other using convex protrusions 109A and 109B (collectively, “convex protrusions 109”). The convex protrusions 109 can provide a spacing distance between thermal transfer components 106 of the thermoelectric space heater 100, as well as an interconnection thoroughfare 112. The spacing between the thermal transfer components 106 can allow for efficient heating and convection of the air around the thermal transfer components 106 to heat an area. The interconnection thoroughfare 112 can be used to contain the electrical connections to each of the heating elements of the thermal transfer components 106. For example, the heating elements can be connected by an electrical circuit board, pinboard, or wires within the interconnection thoroughfares 112. In some cases an electronic control module can be included for the thermoelectric space heater 100 in the interconnection thoroughfare 112, for example, on a circuit board or a pinboard for connecting the heating elements. A tip-over switch can be included in the electronic control module to prevent dangerous conditions when the thermoelectric space heater 100 tips over. In other embodiments, the thermal transfer components and other parts of the thermoelectric heater 100 can be designed such to prevent dangerous conditions even when the thermoelectric space heater 100 tips over. For example, the temperature of the exterior portions of the thermoelectric space heater 100, like the outer edges of the thermal transfer components 106, can be designed to stay below a specified temperature.

The thermal transfer components 106 can have the convex protrusions 109 on one or both sides (e.g. left and right sides as shown) of the thermal transfer components 106. For example, a first thermal transfer component 106 can be substantially flat on one side, and can still be connected to the next thermal transfer component 106 while maintaining the spacing distance by convex protrusions 109 on the next thermal transfer component 106.

The thermal transfer components 106 shown in FIG. 1 each have two convex protrusions on each side. The convex protrusions of the thermal transfer components 106 can be connected to each other, and in some examples the connection can be facilitated by screws or rivets or a weld such as a rolling weld. In other examples, a thermal transfer component 106 can have additional, fewer, or no convex protrusions 109, and the thermal transfer components 106 can be connected in another manner, for example, using bars or bolts. Where no convex protrusions 109 are used, an interconnection thoroughfare 112 can be provided by a tube or conduit that connects the thermal transfer components 106, or by a base or a top of the thermoelectric space heater 100.

In some situations, the inner thermal transfer components 106 (e.g. 106B-106F) can be different from the outer thermal transfer components 106 (e.g. 106A and 106G). For instance, in some cases, the thermal transfer component 106A can be made without convex protrusions 109 on one or both sides. Additionally, the heating elements for the outer thermal transfer components 106 can differ from the inner thermal transfer components 106, as will be discussed further below. For example, the outer thermal transfer components 106 can be made to stay below a certain maximum temperature delta between the ambient temperature and the end temperature (e.g., 85° C.). In some examples, an outer thermal transfer component 106 can be covered by a control panel.

Moving now to FIG. 2, shown is a drawing of an example of a front view of one side of a thermal transfer component 106 of the thermoelectric space heater 100. The thermal transfer component 106 can have a heating channel 133, an insulating channel 136, and insulating holes 139. The thermal transfer component 106 can be said to have a heating area 142 and an insulating area 145. The heating area 142 refers to a center portion of the surface area of each of the plates of the thermal transfer component 106, and the insulating area 145 refers to the periphery of the surface area of each of the plates of the thermal transfer component 106 around the heating area 142.

The heating channel 133 is in the heating area 142 and can be used to contain a heating element of the thermoelectric space heater 100. In some situations a thermal transfer component 106 can have multiple channels 133 for multiple heating elements, and in other situations a single heating channel 133 can be used. The heating channel 133 can be designed to cover a surface area of the thermal transfer component 106. To this end, the heating channel 133 can have a number of curves, and can meander or snake along a height and a width of the thermal transfer component 106 within the heating area 142. The heating channel 133 can have one or both ends opening into one or both of the interconnection thoroughfares 112. As shown in FIG. 2, the heating channel 133 has both ends opening into the bottom interconnection thoroughfare 112. In this way, electrical connections to a heating element in the heating channel 133 can be made in the interconnection thoroughfare 112. In some examples, a single heating element can run the entire length of the heating channel 112. When the convex protrusions 109 are in the heating area 142 as shown, they can become heated. Adjacent convex protrusions 109 of adjacent thermal transfer components 106 can be connected. The connection can provide for heat transfer or conduction between the thermal transfer components 106. In other embodiments, the heating channel 133 can have one end connecting to the bottom interconnection thoroughfare 112 and another end connecting to the top interconnection thoroughfare 112. The thermal transfer component 106 can also have more than one heating channel 133. The form of the heating channel 133 can improve mechanical strength of the thermal transfer component 106.

The insulating channel 136 can be in the insulating area 145 of the thermal transfer component 106. The insulating channel 136 can provide a measure of thermal isolation for an outer edge of the thermal transfer component 106 from the heating channel 133 of the heating area 142. In this way, the outer edge of the thermal transfer component 106 can be cooler than the heating channel 133. The insulating channel 136 can be substantially along the outer edge of the thermal transfer component 106. In some situations the insulating channel 136 can itself compose the outer edge of the thermal transfer component 106, and in other cases, the thermal transfer component 106 can have a flat outer edge extending beyond the insulating channel 136. In other words, the thermal transfer component 106 can have an insulating channel 136 along an outer edge of the thermal transfer component 106 and can have a fin composing the outer edge of the thermal transfer component. In some cases, the insulating channel 136 can contain insulation or an insulating material, and in other cases, the insulating channel 136 can be empty. The insulating material can be cotton.

The thermal transfer component 106 can further have insulating holes 139 in the insulating area 145. The insulating holes 139 can provide a measure of thermal isolation between areas of the thermal transfer component 106 by limiting thermal conduction between areas. For example, the insulating holes 139 can provide thermal isolation between the area of the heating channel 133 and the outer edge of the thermal transfer component 106. The insulating holes 139 can be any shape, including circular, clover-shaped, or kidney-shaped as shown, or can be square, rectangular, ovular, or have another shape. The insulating holes 139 can be stamped in a plate of the thermal transfer component 106 and can be alignment holes, such as rivet holes, or holes with ridges for connecting plates of the thermal transfer component 106 together as will be discussed below. While the insulating holes 139 can be anywhere in the thermal transfer component 106, the insulating holes can be in a fin composing the outer edge of the thermal transfer component 106, and can be used along with, or in lieu of, the insulating channel 136. The insulating holes 139 can also provide for cross-ventilation between the thermal transfer components 106 of the thermoelectric space heater 100.

FIG. 3 shows an example of an exploded view of the thermal transfer component 106. The thermal transfer component 106 can have a plate 160 and a plate 161 that form or compose an exterior of the thermal transfer component 106. The thermal transfer component 106 can also have a heating element 163, and can further have a sheet 166 and a sheet 169. When assembled, the plate 160 and the plate 161 can be connected using rivets, screws, welds, a rolling weld, or another manner.

The heating element 163 can be a flexible electrical wire or cord, and in some examples, can be insulated. In other situations, the heating element 163 can be a rigid heating element. The heating element 163 can be between the sheets 166 and 169. In some examples, the sheets 166 and 169 can be metal foil sheets such as aluminum or tin foil. Where the heating element 163 is flexible, the sheets 166 and 169 can serve to hold the heating element in a particular arrangement or shape. To this end, the sheets 166 and 169 can be formed with a recess or indent with the shape of the heating channel 133, and can be used to hold the heating element 163 in place during manufacture or assembly of the thermal transfer component 106 while positioning the heating element 163 in the heating channel 133. In addition, when assembled in the thermal transfer component 106, the sheets 166 and 169 can help with conduction or other transfer of heat from the heating element 163 to the thermal transfer component 106, while preventing direct contact between the heating element 163 and the thermal transfer component 106, which can prevent damage or influence to the thermal efficiency of the heating element 163. The sheets 166 and 169 can prevent the heating element 163 from coming out of the heating channel 133 and increase ease of assembly and manufacturing efficiency. In some examples, the heating element 163 can be assembled in the heating channel 133 without the sheets 166 and 169.

Looking back to FIG. 1, where a thermoelectric space heater 100 has multiple thermal transfer components 106, each with a heating element 163, the heating elements 163 can be connected using a circuit board, a pinboard or wiring in the interconnection thoroughfare 112. The heating elements 163 can be connected in series or parallel. In other examples there can be a single heating element 163 that goes through all of the thermal transfer components 106, connected through the interconnection thoroughfare 112.

With reference to FIG. 4, shown is an example of a sectional view of the thermal transfer component 106, and a zoomed view of a portion of the thermal transfer component 106. The sectional view of FIG. 4 can correspond to section A-A of the thermal transfer component 106 indicated in FIG. 2. The sectional view of the thermal transfer component 106 shows the plate 160 and the plate 161 of the thermal transfer component 106. The thermal transfer component 106 can have the insulating channel 136, the heating channel 133, the insulating holes 139, and the convex protrusions 109. Here, the plate 160 and the plate 161 each have a convex protrusion 109. In other embodiments, only one (or neither) of the plates of the thermal transfer component 106 can have the convex protrusion 109.

The heating channel 133 can be formed between the plates 160 and 161. Each of the plates 160 and 161 can have an indent that forms the heating channel 133. In other embodiments, only one of the plates 160 or 161 has an indent, and the other plate can be flat, while still forming the heating channel 133 between the plates 160 and 161 when assembled. The heating element 163 can be within the heating channel 133 as shown.

In some aspects like the heating channel 133, the insulating channel 136 can be formed between the plates 160 and 161. Each of the plates 160 and 161 can have an indent that forms the insulating channel 136. In other embodiments, only one of the plates 160 or 161 has an indent, and the other plate can be flat, while still forming the insulating channel 136 between the plates 160 and 161 when assembled.

The insulating holes 139 are also shown in the sectional view. This view illustrates that the insulating holes 139 can be holes through both of the plates 160 and 161. The insulating holes 139 can be stamped in the plates 160 and 161 of the thermal transfer component 106. The insulating holes 139 can also be rivet holes. In other examples, the insulating holes 139 can be alignment holes that aid the connection of the plate 160 to the plate 161, using a ridge, or curl as shown. In some instances the ridge or curl of the insulating hole 139 through the plate 160 can be larger than the ridge or curl of the same insulating hole 139 through the plate 161. In other instances only one of the plates can have the ridge or curl. The outer edge of the thermal transfer component 106 is also shown to have a ridge or curl to connect the plates 160 and 161. In other words, one or both of the plates 160 and 161 can form ridges or curls that facilitate a connection of the plate 160 to the plate 161, both along the outer edge of the thermal transfer component 106 and along edges of the insulating holes 139.

The zoomed-in region shows the heating element 163 within the heating channel 133. In the zoomed view, the sheets 166 and 169 can be seen sandwiched around the heating element 163, between the plates 160 and 161. While the heating elements 163 is within the heating channel 163, the sheets 166 and 169 are between the plates 160 and 161 both inside the heating channel 163 as well as sandwiched between the plates 160 and 161 outside of the heating channel 163. The heating element 163 is located substantially at the center of the heating channel 133 such that there is an air gap or space between the heating element 163 and the heating channel 133. This can prevent temperature imbalances from one side to another side of the thermal transfer component 106, and can prevent the temperature from becoming too high as a result of direct contact.

Moving to FIG. 5, shown is a cut-away drawing of an example of a section of the heating element 163. The heating element 163 can have an inner core 182, a resistive heating wire 184, and an outer insulation layer 186. As mentioned earlier, the heating element 163 can be relatively flexible or can be rigid. The resistive heating wire 184 can be wrapped around the inner core 182 of the heating element 163. Voltage or current applied to the resistive heating wire 184 can cause the resistive heating wire to produce heat. To this end, the resistive heating wire 184 can be wrapped around the inner core 182 with a desired wrapping density in order to produce a desired heating level for the section of the heating element 163 as a result of the resistance per unit length of the resistive heating wire wrapped around the inner core 182. In some examples, the desired wrapping density, and changes in wrapping density, can be achieved by wrapping the resistive heating wire 184 wrapped around the inner core 182 in a spiral winding pattern. In other embodiments, the winding pattern can achieve the desired wrapping density and variations using a square pattern, a pattern of connected loops, or another pattern.

In some situations, the entire heating element 163 has a single desired resistance per unit length of the heating element 163. In that case, the heating element 163 can have a restive heating wire 184 wrapped at a substantially constant wrapping density around the inner core 182 for the entire length of the heating element 163, the constant wrapping density causing the heating element to have the single desired resistance per unit length. In other situations, the heating element 163 can have different desired resistance per unit length for different sections along the length of the heating element 163, to create different heating levels in different locations of the heating element 163. One way to achieve this is to wrap the resistive heating wire 184 with a variable wrapping density, with a higher wrapping density where more heat or more resistance per unit length is desired and a lower wrapping density where less heat or less resistance per unit length is desired. In this way, a single heating element can be used for the entire length of a heating channel while, and the single heating element in the heating channel can provide one or more different heating levels with the single heating element.

The heating element 163 shown in FIG. 5 has a different wrapping density in different areas along its length. While the heating element 163 can be oriented in any way, and can be curved or meandered when assembled, the terms top and bottom are used with specific reference to the orientation of the section of the heating element 163 shown in FIG. 5. The top of the heating element 163 shows the resistive heating wire 184 wrapped around the inner core 182 at different wrapping density than the bottom of the heating element 163. The wrapping density corresponds to the distance that can be measured between the wraps of the resistive heating wire 184 on one side of the inner core 182, where a lower wrapping density corresponds to greater distance and higher wrapping density corresponds to lesser distance. The distance d1 between the spiral structure of the resistive heating wire 184 wrapped around the inner core 182 at the top of the heating element 163 indicates one wrapping density while the distance d2 at the bottom of the heating element 163 indicates another wrapping density in that location. Because d1 is greater than d2, the top of the heating element 163 (corresponding to d1) has a lower wrapping density, and a lesser resistance per unit length, than the bottom of the heating element 163 (corresponding to d2). Generally, lower wrapping density corresponds to a lower heating level, or less heat produced per unit length of the heating element 163. The heating element 163 can be designed, along with the heating channel 133, the insulating holes 139, insulating channels 136 or other components of the thermoelectric space heater 100, such that the does not need over-temperature electrical controls or a tip-over sensor. In other cases, over-temperature electrical control or a tip-over sensor can nevertheless be utilized.

FIG. 6 shows an example of another thermal transfer component 106 that illustrates how different heating regions 191 and 192 of a heating channel can have different heating levels. For example, the heating element 163 can have different resistance per unit length in the region 191 compared to the region 192. In this example, the heating level in the center of the thermal transfer component 106 can be designed to be higher than the periphery. To this end, the region 191 can indicate where the heating element 163 has a higher resistance per unit length, for example by having a higher wrapping density. The region 192 can indicate where the heating element 163 has a lower resistance per unit length, for example by having a lower wrapping density. In this way, the thermal transfer component 106 can produce more heat in the center, which can be transferred to the air by convection, while the outside edge of the thermal transfer component 106 is cooler to the touch.

As shown, the heating element 163 can start with a first wrapping density in region 191 within the heating channel 133, change to another wrapping density in region 192, and then transition back to the first wrapping density. While two regions 191 and 192 are shown, additional regions can be designed, and the wrapping density or resistance per unit length can be abruptly or gradually transitioned along the length of the heating element 163. In some examples, additional heating elements can be used, each with constant or varied resistance per unit length.

Referring back to FIG. 1, the outer thermal transfer components 106 can be designed to have a different heating level than the inner thermal transfer components. In some cases, government, industry, or other regulations can require that a limited temperature that is allowed for the outermost edges of a heater (e.g., 85° C.), while the inner areas can have greater temperatures. For example, the thermal transfer component 106A can have a lower resistance per unit area than the thermal transfer component 106B for the respective heating elements in the respective heating channels. Further, each thermal transfer component 106 of the thermoelectric space heater 100 can be designed with its own respective heating element, causing its own set of heating regions as discussed.

It is emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations described for a clear understanding of the principles of the disclosure. Many variations and modifications can be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure. 

Therefore, the following is claimed:
 1. A thermoelectric heater, comprising: a thermal transfer component comprising a first plate attached to a second plate, wherein a surface area of each of the first plate and the second plate comprise a center heating area and an outer insulating area; a heating channel formed by the first plate and the second plate of the thermal transfer component, the heating channel being between the first plate and the second plate in the heating area; a heating element within the heating channel; a plurality of insulating holes in the outer insulating area; and a fin in the outer insulating area composing an outer edge of the thermal transfer component.
 2. The thermoelectric heater of claim 1, wherein the insulating holes are alignment holes that facilitate a connection of the first plate and the second plate.
 3. The thermoelectric heater of claim 1, wherein the heating element comprises more than one resistance per unit length.
 4. The thermoelectric heater of claim 1, wherein the heating element comprises: an inner core; a resistive heating wire wrapped around the inner core; and an outer insulation layer.
 5. The thermoelectric heater of claim 1, further comprising an insulating channel formed by the first plate and the second plate of the thermal transfer component, the insulating channel being between the first plate and the second plate in the insulating area, wherein the insulating channel provides thermal isolation between the heating area and an outer edge of the thermal transfer component.
 6. The thermoelectric heater of claim 1, wherein the heating element is held substantially at a center of the heating channel by a first sheet and a second sheet sandwiched around the heating element, wherein the first sheet and the second sheet that are sandwiched around the heating element are between the first plate and the second plate of the thermal transfer component.
 7. The thermoelectric heater of claim 1, further comprising another thermal transfer component having another heating element in another heating channel, wherein the another heating element has a different resistance per unit length than the thermal transfer component.
 8. An apparatus, comprising: a thermal transfer component having a height and a width, the thermal transfer component comprising a first plate attached to a second plate; a heating channel formed by at least one of the first plate or the second plate of the thermal transfer component, the heating channel that is formed between the first plate and the second plate, wherein the heating channel meanders along at least a portion of the height and the width of the thermal transfer component; and a heating element within the channel.
 9. The apparatus of claim 8, wherein at least one of the first plate or the second plate comprises a fin along an outer edge of the thermal transfer component.
 10. The apparatus of claim 9, further comprising a plurality of insulating holes through the fin.
 11. The apparatus of claim 10, wherein at least one of the plurality of insulating holes is an alignment hole.
 12. The apparatus of claim 8, further comprising an insulating channel formed by the first plate and the second plate of the thermal transfer component, the insulating channel being substantially along an outer edge of the thermal transfer component.
 13. The apparatus of claim 8, further comprising an insulating channel and a fin formed by the first plate and the second plate of the thermal transfer component, the insulating channel and the fin being substantially along an outer edge of the thermal transfer component.
 14. The apparatus of claim 8, further comprising at least one thermal insulation channel formed by the first plate and the second plate of the thermal transfer component, the insulating channel being substantially along an outer edge of the thermal transfer component.
 15. An apparatus, comprising: a thermal transfer component comprising a first plate and a second plate; a heating channel in a center heating area formed by the first plate and the second plate, wherein the heating channel is between the first plate and the second plate; an insulating channel in an insulating area formed by the first plate and the second plate, wherein the insulating channel is between the first plate and the second plate; and a first foil sheet and a second foil sheet between the first plate and the second plate that hold a heating element in the heating channel, wherein the first foil sheet and the second foil sheet maintain a gap between the heating element and the heating channel.
 16. The apparatus of claim 15, further comprising a fin composing an outer edge of the thermal transfer component.
 17. The apparatus of claim 15, further comprising at least one insulating hole in the insulating area.
 18. The apparatus of claim 15, wherein the heating element comprises: an inner core; and a resistive heating wire wrapped around the inner core, wherein a wrapping density of the resistive heating wire varies along a length of the heating element.
 19. The apparatus of claim 15, further comprising an interconnection thoroughfare formed by a convex protrusion on each of the first plate and the second plate of the thermal transfer component.
 20. The apparatus of claim 15, wherein the thermal transfer component is one of a plurality of thermal transfer components, and wherein the plurality of thermal transfer components are connected by a plurality of convex protrusions of the plurality of thermal transfer components. 